/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_ServoElementSnapshot_h
#define mozilla_ServoElementSnapshot_h
#include "AttrArray.h"
#include "mozilla/TypedEnumBits.h"
#include "mozilla/dom/BorrowedAttrInfo.h"
#include "mozilla/dom/RustTypes.h"
#include "nsAttrName.h"
#include "nsAttrValue.h"
#include "nsChangeHint.h"
#include "nsGkAtoms.h"
#include "nsAtom.h"
#include "MainThreadUtils.h"
namespace mozilla {
namespace dom {
class Element;
}
/**
* A bitflags enum class used to determine what data does a ServoElementSnapshot
* contains.
*/
enum class ServoElementSnapshotFlags : uint8_t {
State = 1 << 0,
Attributes = 1 << 1,
Id = 1 << 2,
MaybeClass = 1 << 3,
OtherPseudoClassState = 1 << 4,
CustomState = 1 << 5,
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ServoElementSnapshotFlags)
/**
* This class holds all non-tree-structural state of an element that might be
* used for selector matching eventually.
*
* This means the attributes, and the element state, such as :hover, :active,
* etc...
*/
class ServoElementSnapshot {
typedef dom::BorrowedAttrInfo BorrowedAttrInfo;
typedef dom::Element Element;
// TODO: Now that the element state shares a representation with rust we
// should be able to do better and not use the internal type.
typedef dom::ElementState::InternalType ServoStateType;
public:
typedef ServoElementSnapshotFlags Flags;
explicit ServoElementSnapshot(
const Element&);
~ServoElementSnapshot() {
MOZ_ASSERT(NS_IsMainThread());
MOZ_COUNT_DTOR(ServoElementSnapshot);
}
bool HasAttrs()
const {
return HasAny(Flags::Attributes); }
bool HasState()
const {
return HasAny(Flags::State); }
bool HasOtherPseudoClassState()
const {
return HasAny(Flags::OtherPseudoClassState);
}
/**
* Captures the given state (if not previously captured).
*/
void AddState(dom::ElementState aState) {
if (!HasAny(Flags::State)) {
mState = aState.GetInternalValue();
mContains |= Flags::State;
}
}
/**
* Captures the given element attributes (if not previously captured).
*
* The attribute name and namespace are used to note which kind of attribute
* has changed.
*/
void AddAttrs(
const Element&, int32_t aNameSpaceID, nsAtom* aAttribute);
/**
* Captures the given element custom states.
*/
void AddCustomStates(Element&);
/**
* Captures some other pseudo-class matching state not included in
* ElementState.
*/
void AddOtherPseudoClassState(
const Element&);
/**
* Needed methods for attribute matching.
*/
BorrowedAttrInfo GetAttrInfoAt(uint32_t aIndex)
const {
MOZ_ASSERT(HasAttrs());
if (aIndex >= mAttrs.Length()) {
return BorrowedAttrInfo(nullptr, nullptr);
}
return BorrowedAttrInfo(&mAttrs[aIndex].mName, &mAttrs[aIndex].mValue);
}
const nsAttrValue* GetParsedAttr(nsAtom* aLocalName)
const {
return GetParsedAttr(aLocalName, kNameSpaceID_None);
}
const nsAttrValue* GetParsedAttr(nsAtom* aLocalName,
int32_t aNamespaceID)
const {
MOZ_ASSERT(HasAttrs());
uint32_t i, len = mAttrs.Length();
if (aNamespaceID == kNameSpaceID_None) {
// This should be the common case so lets make an optimized loop
for (i = 0; i < len; ++i) {
if (mAttrs[i].mName.Equals(aLocalName)) {
return &mAttrs[i].mValue;
}
}
return nullptr;
}
for (i = 0; i < len; ++i) {
if (mAttrs[i].mName.Equals(aLocalName, aNamespaceID)) {
return &mAttrs[i].mValue;
}
}
return nullptr;
}
bool IsInChromeDocument()
const {
return mIsInChromeDocument; }
bool SupportsLangAttr()
const {
return mSupportsLangAttr; }
bool HasAny(Flags aFlags)
const {
return bool(mContains & aFlags); }
bool IsTableBorderNonzero()
const {
MOZ_ASSERT(HasOtherPseudoClassState());
return mIsTableBorderNonzero;
}
bool IsSelectListBox()
const {
MOZ_ASSERT(HasOtherPseudoClassState());
return mIsSelectListBox;
}
private:
// TODO: Profile, a 1 or 2 element AutoTArray could be worth it, given we know
// we're dealing with attribute changes when we take snapshots of attributes,
// though it can be wasted space if we deal with a lot of state-only
// snapshots.
nsTArray<AttrArray::InternalAttr> mAttrs;
nsTArray<RefPtr<nsAtom>> mChangedAttrNames;
nsTArray<RefPtr<nsAtom>> mCustomStates;
nsAttrValue mClass;
ServoStateType mState;
Flags mContains;
bool mIsInChromeDocument : 1;
bool mSupportsLangAttr : 1;
bool mIsTableBorderNonzero : 1;
bool mIsSelectListBox : 1;
bool mClassAttributeChanged : 1;
bool mIdAttributeChanged : 1;
};
}
// namespace mozilla
#endif
